Evaluation of the effect of concentration and duration of application of sodium ascorbate hydrogel on the bond strength of composite resin to bleached enamel

Abstract

Aim:The effect of different concentrations of hydrogel of sodium ascorbate on bond strength of bleached enamel for varying periods of time and the mode of failure was evaluated.Materials and Methods:Seventy enamel surfaces were obtained from 35 human extracted premolars. Specimens were divided into four groups: no bleaching (control), bleaching with carbamide peroxide gel, bleaching and application of 10% / 20% sodium ascorbate hydrogel for 30, 60, 120 min. Surfaces were bonded with a total etch bonding system and composite resin. Specimens were tested for shear bond strength. Mode of failure was determined by stereomicroscope. Data were analyzed using a two-way analysis of variance, and Scheffe's post hoc test.Results:Sodium ascorbate hydrogel application following bleaching increased the resin-enamel bond strength and was directly proportional to its duration of application. However, there was no difference in bond strength with an increase in the concentration of sodium ascorbate hydrogel.Conclusion:Immediate bonding of composite resin to bleached enamel is possible after treatment with antioxidant sodium ascorbate hydrogel.